Actuating mechanism for plier type devices



Nov. 1, 1966 LOVELACE 3,282,137

ACTUATING MECHANISM FOR PLIER TYPE DEVICES Filed Dec. 30, 1964 INVENTOR. 52 5o A lO/VTA'HAOVZ 465 JTTO/QA/EY United States Patent 3,232,137 ACTUATING MECHANISM FOR PLIER TYPE DEVICES Monte H. Lovelace, San Fernando, Calif., assignor to The Bendix Corporation, North Hollywood, Calif., a corporation of Delaware Filed Dec. 30, 1964, Ser. No. 422,274 6 Claims. (Cl. 8l302) This invention relates to a force and motion transmitting device, and more particularly to an actuating mechanism for implements of the plier type.

Hand-operated implements of the type referred to, whether they be holding devices like pliers or cutting devices, in general are formed of two mating halves which are pinned together at some off-center axis to permit the operator to gain some significant mechanical advantage through the application of a force to the handles at a distance from said axis which is greater than the distance from said axis to the working jaws or cutters. One of the shortcomings of this arrangement is that the pivot pin and the holes or passages through which the pin passes, inevitably wear, and as such wear takes place, the action becomes loose and sloppy. In the case of pliers, the jaws no longer push directly against each other, but may slip past each other to some extent. In the case of cutting devices such as end nippers, the cutting edges ultimately fail to meet and operation is impaired accordingly. At the same time, the operator is likely to find that his hand is pinched by the sudden sideways motion of the two halves as they slip by each other. It is therefore an object of the present invention to provide a motion and force transmitting device suitable for plier type implements as well as other applications in which the usual pivot pin is eliminated.

It is another object of the present invention to provide an actuating mechanism for plier-type devices in which the action is consistent and not subject to lateral displacement of the working jaws or handles.

It is another object of the present invention to provide an actuating mechanism for plier-type devices in which the danger of pinching the operators hand is minimized.

It is a further object of the present invention to provide an actuating mechanism which will meet the above objectives and which still provides adequate mechanical advantage for many applications.

Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings, in which:

(1) FIGURE 1 is a perspective view of one embodiment of my invention; i

(2) FIGURE 2 is a exploded perspective view showing the parts of the device of FIGURE 1; and

(3) FIGURE 3 is a perspective view of another modification of my invention.

Referring now to FIGURES 1 and 2, my device con sists of a pair of jaw sections It and 12 which are normally held in a somewhat open position as shown in the dotted lines of FIGURE 1, but which may be moved to the closed position as shown in the solid lines through the application of forces tending to squeeze the handle sections 114 and 16 together as shown by the arrows. Positioned between the jaw sections and the handle sections are a pair of flexure sections I8 and 20. The handle sections are cut out to form an opening at numeral 22 with a pair of projections 24 and 26 which act as stops. At the oppoiste side of opening 22 from the stops is a pivot point consisting of a hinge portion 28 which is secured by means-of a pin 30. At the oppos1te end of the opening between the fiexure sections 18 and ice 20 is a second hinge portion 32 secured by means of a pin 34-.

From consideration of the exploded view, FIGURE 2, the relationships of the parts may be more easily ascertained. It will be observed that the entire tool consists of two parts which are, or may be, identical except for the mating hinge portions 28 and 32. Actually, the small pin receiving blocks which make up the hinge portions could be welded to the identical parts after the parts are formed. Any suitable hinge structure could be used, so long as it is adequately free from susceptibility to twisting or looseness. A large opening 36 is shown at the inside of jaw sections 10, 12 which is for the purpose of avoiding interference near the pivot point of the jaws.

It will be observed that the fiexure sections 18 and 2d are shown in both dotted and solid lines in FIGURE 1. When the tool is at rest, these flexure sections will assume the position taken by the dotted lines. When forces are applied to the handles, as shown by the arrows, these forces act around the pivot 28 and cause the fiexure sections 18 and 20 to bow outwardly as shown in the solid lines. This results in a rotating force being applied around pivot 32 which moves jaws It) and 12 in a closing direction. It will be recognized that the travel of these jaws is somewhat limited, but for many kinds of work, especially small electronic assembly work, this small travel is adequate, and the advantage afforded by the positive action and freedom from lateral slipping is of far more importance than the travel limitation.

For some operations, the embodiment shown in FIG- URE 3 will prove useful. It utilizes much the same operating principle but is formed of a solid unitary piece of material so that no hinge pins or hinge blocks are used whatever. This device is shown in the solid lines in its normal, unloaded, position, and the jaws 4t 42 are shown open. The position with the jaws closed is shown by the dashed lines. Handle portions 44 and 46 are connected to the jaws 40 and 42 through a pair of flexure sections 48 and 50. An opening 52 is formed at the base of the handle sections, and a pair of stops 54 and 56 are supplied to prevent over-travel of flexure sections through excessively vigorous action of the operator. Replacing the hinge portions of the FIGURE 1 embodiment are a pair of solid flexure sections 58 and 60 which act as hinges in essentially the manner described. The forces which squeeze handles 44 and 46 together cause the structure to pivot around fiexure 58 and cause flexure sections 48 and 50 to bow outwardly. This, in turn, causes pivoting of the structure around flexure 6t and the jaws 40 and 42 are moved in a closing direction. An opening 62 is provided which, in combination with the opening between flexure sections 50 and 48, is sized and located to afiord the desired resilience for fiexure 60. Obviously, opening 52 in combination with the opening between flexure sections 48 and 50 also may be sized and located to control the resilience of flexure 58. This embodiment will normally afford somewhat less travel at the jaws than the device of FIGURES 1 and 2, but it has absolutely no relatively moving parts to wear.

While only two embodiments have been shown and described herein, modifications may be made to suit requirements. Although the actuating mechanism of the invention has been shown herein in connection with a long-nosed plier device, it is obviously also useful-for cutting devices such as end nippers or diagonal cutters. It is also generally useful as a force and motion transmitting device where the common type of pinned pivot is unsuitable. Such devices may be formed of any suitable material such as steel or other metal alloys, or suitable plastics in some instances.

I claim:

1. A hand tool comprising a unitary piece of solid material including a pair of elongated jaws which are normally displaced from each other;

means defining a first opening at the base of said jaws;

a gripping portion consisting of a pair of handle members adapted to be squeez'ed toward each other by an operator;

means defining a second opening at the base of said handle members, said means including a pair of projections on said handle members acting as stops;

an intermediate section positioned between said openings including first and second flexure sections extending longitudinally between said handle sections and said jaws;

a third flexure section positioned between said handle sections and adjacent said second opening;

and a fourth flexure section positioned adjacent said first opening, said third flexure section serving as a pivot around which the forces exerted on said handle members are applied to said first and second flexure sections and said fourth flexure section serving as a pivot around which forces from said first and second flexure sections are applied to said jaws to move said jaws toward each other.

2. A hand tool comprising a unitary piece of solid material including a pair of elongated jaws which are normally displaced from each other;

means defining a first opening at the base of said jaws;

a gripping portion consisting of a pair of handle members adapted to be squeezed toward each other;

means defining a second opening at the base of said handle members;

first and second fiexur'e sections extending longitudinal-1y between said handle sections and said jaws;

a third flexure section positioned between said handle sections and adjacent said second opening;

.and a fourth flexure section positioned adjacent said first opening, said third flexure section serving as a pivot around which th'e forces exerted on said handle members are applied to said first and second flexure sections and said fourth flexure section serving as a pivot around which forces from said first and second flexure sections are applied to said jaws to move said jaws toward each other.

3. In a hand tool comprising a pair of elongated jaws which are normally displaced from each other and a pair of handles operativ'ely connected to said jaws to cause said jaws to move toward each other when said handles are moved toward each other, means for transmitting the force from said handles to said jaws including:

first and second flexible sections extending longitudinally between said handle sections and said jaws;

1a first pivot section operatively positioned between said handles and said fiexur'e sections around which the forces exerted on said handle members are applied to said flexure sections; and

a second pivot section operatively positioned between said flexure sections and said jaws around which the forces from said first and second flexure sections are applied to said jaws.

4. In a hand tool including a pair of elongated jaws which are normally displaced from each other and a pair of handles operatively connected to said jaws to cause said jaws to move toward each other, means for transmitting the force from' said handles to said jaws comprising:

a first flexure section extending longitudinally between one of said handles and one of said jaws to form a first part,

a second flexure section extending longitudinally between the other of said handles and the other of said jaws to form a second part, and

first and second mating pivot sections attached to said parts at each end of said flexure sections.

5. A motion and force transmitting device consisting of a'unitary piece of solid material including a pair of longitudinally extending input members to which an in'iut force may be applied in a direction to force said members toward each other, a pair of longitudinally extending output members adapted to be forced together in response to said input force, and means for transmitting the force from said input members to said output members comprising:

first and second flexure sections extending longitudinally between each of said pairs of input members and output members, respectively,

a first pivot section operatively positioned between said input members and said flexure sections around which said input force is transferred to said flexure sections, and

a second pivot section operatively positioned between said flexure sections and said output members around which the force applied to said flexure sections is transferred to said output members.

6. A motion and force transmitting device including a pair of longitudinally extending input sections to which an input force may be applied in a direction to force said sections toward each other, a pair of longitudinally extending output sections adapted to be forced together in response to said input force, and means for transmitting the force from said input sections to said output sections comprising:

first and second flexure sections extending longitudinally between each of said pairs of input sections and output sections, respectively,

a first pivot section operatively positioned between said input sections and said flexure sections around which said input force is transferred to saidfiexure sections, and

a second pivot section operatively positioned between said flexure sections and said output sections around which the force applied to said flexure sections is transferred to said output sections.

References Cited by the Examiner UNITED STATES PATENTS 1,109,834 9/1914 Hamachek 8l302 2,376,135 5/1945 Fresher 8l-43 X 2,901,933 9/ 1959 Wieser. 3,167,981 2/1965 Kern 81-43 FOREIGN PATENTS 1,088,439 9/ 1960 Germany.

WILLIAM FELDMAN, Primary Examiner.

MILTON S. MEHR, Examiner. 

1. A HAND TOOL COMPRISING A UNITARY PIECE OF SOLID MATERIAL INCLUDING A PAIR OF ELONGATED JAWS WHICH ARE NORMALLY DISPLACED FROM EACH OTHER; MEANS DEFINING A FIRST OPENING AT THE BASE OF SAID JAWS; A GRIPPING PORTION CONSISTING OF A PAIR OF HANDLE MEMBERS ADAPTED TO BE SQUEEZE TOWARD EACH OTHER BY AN OPERATOR; MEANS DEFINING A SECOND OPENING AT THE BASE OF SAID HANDLE MEMBERS, SAID MEANS INCLUDIG A PAIR OF PROJECTIONS ON SAID HANDLE MEMBERS ACTING AS STOPS; AN INTERMEDIATE SECTION POSITIONED BETWEEN SAID OPENINGS INCLUDING FIRST AND SECOND FLEXURE SECTIONS EXTENDING LONGITUDINALLY BETWEEN SAID HANDLE SECTIONS AND SAID JAWS; A THIRD FLEXURE SECTION POSITIONED BETWEEN SAID HANDLE SECTIONS AND ADJACENT SAID SECOND OPENING; AND A FOURTH FLEXURE SECTION POSITIONED ADJACENT SAID FIRST OPENING, SAID THIRD FLEXURE SECTION SERVING AS A PIVOT AROUND WHICH THE FORCES EXERTED ON SAID HANDLE MEMBERS ARE APPLIED TO SAID FIRST AND SECOND FLEXURE SECTIONS AND SAID FOURTH FLEXURE SECTION SERVING AS A PIVOT AROUND WHICH FORCES FROM SAID FIRST AND SECOND FLEXURE SECTIONS ARE APPLIED TO SAID JAWS TO MOVE SAID JAWS TOWARD EACH OTHER. 